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WI BIT.

APPLICATION man new. 191e.

1,308,609'. Patented July 1, 1919.

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Zz'izeesxse 63,. zwaaien WILLIAM SAY, OF LONDON, ENGLAND.

BIT.

Specification of Letters Patent.

Patented July 1, 1919.

Application led December 4, 1916. Serial No. 134,984.

To all 'whom t may concern:

Be it known thatI, WILLIAM SAY, a subject of the King of Great Britain,residing at London, England, have invented certain new and usefulImprovements in Bits, of which the following is a specication.

f This invention relates to that 4class of bit, auger or the likel foruse with an ordinary brace, lathe chuck or equivalent, having removablepoints and removable and adjustable cutting knives so that should thepoint get broken, or the blade broken or re quire sharpening, both canbe removed and renewed instead of the whole bit being scrapped as isnecessary with those having fixed points and blades.

My'present invention consistsrof an improved construction of suchdevicesandconsists in constructing a bit for cutting circular holes in woodfrom a stem suitable for attachment to an ordinary brace yor chuck, suchstem having a hole in the end for securing| `a pointed rod with thepoint either eccentric or concentric to the rod and a boss or extensionat the same end for carrying the cuttingblade, both' pointed end andblade being adjustable. The blade or knife may be so positioned that itscutting point or edge may be varied with regard to the center pointwithin certain limits so that` by this means holes. of variousdiametersmay be cut in addition to those effected by positioning thecenter point should the latter be eccentric to the rod.

My invention will be clearly understood from the following descriptionaided by thev annexed drawings in which:-

Figure 1 is a front view of my improved bit, in which the blade iscapable of being fixed solely in one position.

Fig. 2 is a side view of same, and

Fig. 3 a front view Aof the bit as applied to a sheet of wood. l

Fig. 4 is a plan of the bit.

Fig. 5 is a front elevation of the bit, in which the blade can be fixedin varied positions. i

Fig. 6 is a section on the line a a of Fig. 5.

Fig. 7 is a back elevation of the bit shown in Fig. 5.

For the purpose of my invention and as shown in Figs. 1 and 2 I form thestem A of the bit with one end B shaped to fit the ordinary brace, chuckor equivalent, and in the other end and centrally of the stem a verticalhole C is formedto receive a rod D having a point Ey atone end whichpro-l jects the desired distance beyond the end of the stem A, the rod Dbeing held in place by a set screw F inserted in a screw threaded holein the stem and leading to the hole C therein.

Projecting from the stem A is an arm or boss G preferably having adownwardly projecting angular end H, and in this end a slot I is cut andtherein is positioned the shank J of a knife K, the cutting edge L ofwhich projects the desired distance, and to secure this knife K in placeI employ a set screw M which is inserted in the outer end of the armorboss and passes through the knife shank to hold it firmly in place.

By this construction the end wall N of the slot forms a backing andresistance to the knife K so that perfect cutting by the knife K, whenrevolved about the point in the usual manner, is insured.

j In the modified structure shown by Figs. 5 to 7 I form at an angle tothe stem A and across the face of the arm or boss G a slot P having aback wall Q, in which I form two screw threaded holes for receivingscrews R, S, the screw threads of the hole preferably extending into theside walls of iiliesslot P for further grip of the screws ,At or nearlyat right angles to the slot P I form a hole C leading from the hole C tothe outer wall ofthe boss G, the hole C leading through the slot.

I construct the shank J of the knife K with a hole J and I also form therear of the shank with reverse angular edge portions T, U, or bearingpoints for the screws R,`S.. When the knife shank J is inserted in theslot a pin V is passed through the hole C in the boss G and the hole Jin `the knife shank to hold the knife in the boss G. The screw holes forthe screws R and S are formed centrally in relation to the slot P and,as a consequence, a portion of the screw threads is cut in opposite sidewalls of the slot as indicated in dotted lines by Fig. 6, it beingeasier from a practical construction to form these threaded openingscompletely through the arm or boss than only partially therethrough.

The point E in "the construction shown by Figs. 5 to 7 is eccentric tothe rod D and the latter is provided with two or more recesses W at thepart in alinement with the hole in the boss, one of which recesses isengaged by the pin V.

In assembling the appliance the rod D is first placed in the hole C andthen the knife K is placed in its slot, the pin V is then passed throughits hole in the boss and the opening in the knife K to provide av pivotfor the latter and to engage one of the recesses W in the rod D. Byoperating the screws R, S the knife can be adjusted to the desiredposition, `that is to say, the top screw R can be loosened and the lowerscrew S adjusted into the boss Gto project the cu-tting edge of the.blade forward to the desired degree and by reason of the knife beingpositioned at the angle the cutting edge or point will be positioned ata greater distance from the point E and vice versa. By tightening `thescrews R, S, the knife K will be secured in adjusted position and thepin V will also be tightly clamped in place and all the movable partsfirmly held.

The adjustment of the knife K is not very extensive, and movementthereof outwardly from the boss will not turnthe cutting .edge to anyappreciable vdegree away from a practical cutting position.- In otherwords, the flat sideof the blade will not be brought into an angularresistingposition relatively to the circular line of cut described bythe knife when rotated .by the bit stem. The rod D with the eccentricpoint E can be turned in its opening or socket by loosening the pin V tobring the said point nearer to the blade, the said pin V being thencaused to engage the recess W `opposite that shown by Fig. 5. Thisadjustment of the rod will produce openings curt by therknife K ofdifferent sizes, and provides means with the adjustable knife tomaterially increase the range of adjustment.

lVhat I claim is l. A bit comprisinga stemhaving a boss at its lower endextending at substantially a right angle thereto, the boss having anopening in its lower end in vertical alinement with the axis of the stemand also having a slot near its free end opening outwardly through oneside thereof, va rod secured in said boss opening and rhaving asubstantially straight pointed extremity,

'provided with an extension arranged at substantially a right angle tothe stem, said boss having a vertical slot opening outwardly through oneside near the free end thereof and a vertical opening extending throughits lower end in vertical alinement with the stem, a rod secured in saidboss opening and having a substantially straight pointed free extremityeccentrically positioned relatively to the axis of the rod, a flat knifehaving a shank adjustably mounted in said slot, and means rfor securingthe rod and knife, respectively, in the opening and slot.

3. Aqbit comprising a stem having a hole in its lower end for a pointedrod, a boss or arm having a slot cut at an angle to the stem and a holeat a right angle to said slot reaching to the hole in the stem, screwsengaging the back wall of the slot, a knife having a hole in its shankand bearing portions for the screws, and a pin engaging the hole in the`arm and passing through the hole in the sh ank of the knife and engagingthe rod, the screws engaging said bearing portions and serving tosecurethe knife and pin in fixed positions.

4f. A bit comprising a stem having a hole in its lower end, .a pointedrod having its point eccentric to the axis of the rod, a boss or armhaving a slot cut at an angle to the stem and a hole at a right angle tosaid slot reaching to the hole'in the stem, screws en* gaging the backwall of the slot, a knife having a hole in its shank and bearingportions for the screws, a pin engaging the hole in the arm and passingthrough the hole in the shank of the knife and engaging the rod, the.screws engaging said bearing portions and serving to secure the knifeand pin in xed positions.

In testimony whereof I have hereunto set my handin presence of twosubscribing witnesses.

WILLIAM SAY.

Witnesses F. C. SMITH, WM. V. BROWN.

Copies yof this patent may be vobtained for-five cents each, byaddressing the Commissioner of Patents,

' Washington, D. C.

